Solder return for wave solder nozzle

ABSTRACT

A solder return apparatus for a wave solder machine that collects solder exiting a nozzle and returns the solder to a solder reservoir while limiting the degree to which the solder can splash onto electronic substrates (e.g., printed circuit boards), components of the wave solder machine, and/or the like. The apparatus includes a mounting section that may be placed over an upper surface of the nozzle and a collection section that collects the solder and returns the solder to the solder reservoir. The collection section includes a trough having an opening in a bottom wall of the trough and a flow control member that can adjust a quantity of solder exiting the trough as well as the velocity of the solder exiting the trough. One or more deflection plates can be mounted so as to extend from the trough into solder in the solder reservoir to further contain the solder and limit the degree to which splashing solder can reach unintended locations.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/408,958, filed on Feb. 29, 2012, entitled “Solder Return for WaveSolder Nozzle,” which is a divisional of U.S. patent application Ser.No. 12/725,236, filed Mar. 16, 2010, entitled “Solder Return for WaveSolder Nozzle,” now U.S. Pat. No. 8,146,792, all the contents of whichare incorporated herein by reference.

BACKGROUND

Fundamental to the electronics manufacturing industry is the requirementto make a series of electrical connections (e.g., with a solder alloy)to create electrical circuits and ultimately a functional device withfinal assembly. Wave soldering machines allow a large quantity ofelectrical connections between various components to be quickly andefficiently made. In a wave soldering machine, an electronic substrateis typically moved by a conveyor on an inclined path past a fluxingstation, a preheating station, and a station at which at least one waveof solder is caused to well upwardly through a nozzle and contactvarious portions of the electronic substrate to be soldered.

Wave soldering machines typically utilize tin-lead alloys as the soldermaterial which has been the industry norm for over 40 years. Morerecently however, tin-lead alloy solder is being replaced with lead-freealloys. Often, this change is mandated by international legislation.With current wave soldering apparatus and methods, the advent oflead-free solders has led to reduced process yields and increasedprocess costs. The ability of currently available equipment and processtechniques to accommodate lead-free solders and newer and morechallenging products, regardless of the solder alloy, is limited.Additionally, lead-free solders cost more than do tin-lead or othertypes of solder. As a result, the desire of wave solder operators andowners to reduce the waste of lead-free solders has increased.

SUMMARY

Disclosed herein is an apparatus including a mounting member formounting the apparatus to a nozzle and a collection memberinterconnected to the mounting member such that the collection member isoperable to receive liquid from the nozzle and pass liquid to areservoir. The collection member includes a trough for receiving liquidfrom the nozzle that includes a bottom wall and at least one slot withinthe bottom wall for allowing liquid to pass out of the trough, and aflow control member that is adjustably mounted below the trough. Thebottom wall and the flow control member define a chamber for receivingliquid from the trough and passing liquid into the reservoir.

The mounting member may include an aperture that is sized to rest over atop surface of the nozzle. The aperture may allow liquid to pass fromthe nozzle into the collection member. The mounting member may includean elongated plate that is sized to substantially cover a top surface ofthe nozzle and/or may be sized to hang over a front flange of thenozzle.

The trough may include first and second end walls and a front wall, eachof which may extend upwardly from the bottom wall. The first and secondend walls, the front wall and the bottom wall may define a receivingarea for receiving liquid from the nozzle. A deflection plate may beinterconnected to the trough and may be operable to extend into thereservoir. The deflection plate may be mounted to the front wall, may besubstantially perpendicular to at least one of the bottom wall and theflow control member, and/or may further define the chamber. The frontwall may include a hook member on an upper portion thereof opposite fromthe bottom wall.

The flow control member may include at least one fastener extendingsubstantially perpendicularly therefrom that adjustably interconnectsthe flow control member to the trough. The at least one fastener mayextend through the at least one slot. A mounting tab may be disposedwithin the at least one slot, and the at least one fastener may extendthrough the mounting tab. The flow control member may include anelongated plate.

Also disclosed herein is a wave soldering station including a reservoirholding solder, a wave soldering assembly protruding from the reservoirincluding a solder nozzle, and a collection member interconnected to thesolder nozzle that includes a trough for receiving solder from thesolder nozzle and an aperture through the trough for returning thesolder to the reservoir.

The solder nozzle may include a top surface that includes at least oneaperture for expelling solder from the wave soldering assembly, and thecollection member may include a mounting member that is attached to thetop surface. The solder nozzle may include a front flange that extendsfrom the top surface towards a bottom of the reservoir, and the mountingmember may hang over the front flange. The trough may include a bottomwall that is disposed above a surface of solder in the reservoir andbelow the top surface of the solder nozzle. The bottom wall may bedisposed substantially halfway between the surface of solder in thereservoir and the top surface of the solder nozzle.

The collection member may include a deflection plate that generallyextends from the bottom wall into the solder in the reservoir. Thesolder nozzle may include a front surface that extends from the topsurface into the reservoir, and the front surface may face thedeflection plate. The collection member may further include a flowcontrol member that is adjustably mounted to the trough and thatcontrols a flow rate of solder exiting the aperture. The flow controlmember may be disposed between the deflection plate and the front wall.The flow control member may be disposed between the bottom wall of thetrough and the surface of solder in the reservoir. The deflection plate,the front wall of the solder nozzle, the bottom wall of the trough andthe flow control member may define a chamber for receiving solder fromthe trough.

Also disclosed herein is a method of using a wave solder machineincluding operating the wave solder machine to pump solder from a solderreservoir through at least one aperture of a solder nozzle to form asolder wave, receiving solder from the solder wave in a trough that isinterconnected to the solder nozzle, and allowing the solder to flowthrough an opening in a bottom wall of the trough. The bottom wall isdisposed above a surface of solder in the solder reservoir and below theat least one aperture of the solder nozzle.

After the allowing operation, the method may include receiving thesolder on a plate, and allowing the solder to flow from the plate intothe solder reservoir. The plate may be disposed above the surface ofsolder in the solder reservoir and below the bottom wall of the trough.The method may include adjusting the plate at least one of towards andaway from the bottom wall of the trough. The method may include movingan electronic substrate over the solder nozzle, and this may includemoving a bottom surface of the electronic substrate through the solderwave. The method may include receiving solder from the trough in thereservoir, and continuing to operate the wave solder machine to pump thesolder received in the reservoir from the trough through the at leastone aperture of the solder nozzle to form the solder wave.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a wave soldering machine according toone embodiment.

FIG. 2 is a perspective view of a wave soldering station of the wavesoldering machine of FIG. 1.

FIG. 3 is a perspective view of a solder nozzle and a solder returnapparatus of the wave soldering station of FIG. 2.

FIG. 4 is a sectional view of the solder nozzle and a solder returnapparatus along the lines 4-4 of FIG. 3, the apparatus being disposedwithin a solder reservoir.

FIG. 5 is a perspective view of a solder nozzle and a solder returnapparatus of the wave soldering station of FIG. 2 according to anotherembodiment.

FIG. 6 is a sectional view of the solder nozzle and solder returnapparatus along the lines 6-6 of FIG. 5, the apparatus being disposedwithin a solder reservoir.

FIG. 7 is a flowchart illustrating a method of using a wave solderingmachine using any of the solder return apparatuses disclosed herein.

DETAILED DESCRIPTION

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and are herein described in detail. It shouldbe understood, however, that it is not intended to limit the inventionto the particular form disclosed, but rather, the invention is to coverall modifications, equivalents, and alternatives falling within thescope and spirit of the invention as defined by the claims.

FIG. 1 illustrates a perspective view of a wave soldering machine orapparatus 10 according to one embodiment. As shown, the wave solderingapparatus 10 may include a housing 11 that contains a number of workingstations such as a flux application station 12, a preheat station 14,and a wave soldering station 16. A controller (not shown) having anoperation monitor 18 may control operation of the wave solderingapparatus 10 in a well-known manner. As shown, an electronic substrate20 (e.g., printed circuit board) may be moved by a conveyor 22 along apath (e.g., inclined) past the flux application station 12, thepreheating station 14, and, finally, the wave soldering station 16.

At the flux station 12, any appropriate soldering flux (e.g., 2220-VFand 959 soldering fluxes provided by Kester of Itasca, Ill. and EF-6100soldering flux provided by Alpha Metals of Jersey City, N.J.) may beapplied to a surface of the electronic substrate 20 to be soldered. Forinstance, soldering flux may be deposited at a rate of less than 600micrograms of flux solids per square inch of surface area of theelectronic substrate. At the preheat station 14, the electronicsubstrate may be heated to any appropriate temperature (e.g.,approximately 100° C.). At the wave soldering station 16, one or moresolder waves (not shown in FIG. 1) may be caused to well upwardly out ofone or more solder nozzles and contact various portions of theelectronic substrate to be soldered.

Turning now to FIG. 2, the wave soldering station 16 is shown apart fromthe rest of the wave soldering apparatus 10. As shown, the wavesoldering station 16 may include a solder bath or reservoir 24 thatcontains a supply of molten solder (e.g., lead-free solder, not shown).As used herein, the “solder bath” or “solder reservoir” may mean thewalls or other structure containing the solder and may not necessarilyinclude the solder itself. It should be appreciated that the solderreservoir 24, and even the wave soldering station 16 may, in general, besometimes broadly referred to as a “solder pot.” In any event, the wavesoldering station 16 may also include a first wave soldering assembly 28having a first nozzle 32 that extends up above solder contained withinthe solder reservoir 24, and a second wave soldering assembly 30 havinga second nozzle 38 that extends up above solder contained within thesolder reservoir 24.

The first nozzle 32 may produce a “first wave” of solder which may be aturbulent wave, a chip wave, and/or the like, and may be useful forobtaining an initial coverage of solder on the various components of theelectronic substrate 20. The second nozzle 38 may produce a “main wave”which also may be any appropriate type of wave and in some instances mayproduce a smoother wave than that produced by the first nozzle 32. Oneor more of the first and second nozzles 32, 38 may produce a rotary chipwave (e.g., about 1 inch wide) and/or a wide chip wave (e.g., about 2 ½inches wide). The first wave soldering assembly 28 may include first andsecond side plates 52, 54 extending upwards generally perpendicularlyfrom the first nozzle 32 for limiting the amount of solder that can dripover the lateral sides of the first wave soldering assembly 28.Similarly, the second wave soldering assembly 30 may also include firstand second side plates 56, 58 for limiting the amount of solder that candrip over the lateral sides of the second wave soldering assembly 32.

Although not illustrated, each of the first and second wave solderingassemblies 28, 30 may include one or more pumps to pump solder from thesolder reservoir 24 through any appropriate ducting to the first andsecond nozzles 32, 38 to create the first and main waves. It should beappreciated that the controller (not shown, discussed above) may be usedto control operation of the pumps to adjust a height, flow rate, etc. ofthe first and main waves. Additionally, although two wave solderingassemblies 28, 30 are illustrated, the principles taught herein may beapplied to wave soldering machines incorporating only a single wavesoldering assembly or wave soldering machines incorporating more thantwo wave soldering assemblies. A solder return apparatus 100 ispartially illustrated in FIG. 2, and serves to return solder to thesolder reservoir 24 while reducing the amount of solder that can splashand stick (e.g., in the form of solder balls) onto components of thewave soldering machine 10, electronic substrates 20 within the wavesoldering machine 10, and/or the like. This solder return apparatus 100will be described more fully below.

With reference now to FIGS. 3 and 4, one embodiment of a solder returnapparatus 100 is illustrated as being mounted onto the first nozzle 32,although it should be appreciated that the solder return apparatus 100could also be mounted to the second nozzle 38 of the second wavesoldering assembly 30 or other nozzles (the second nozzle 38 of secondwave soldering assembly 30 being shown in FIG. 2). In any event and withinitial reference to the first nozzle 32, the first nozzle 32 includes afront wall 102 and a rear wall (not illustrated), each of which mayextend into and be appropriately secured within the solder reservoir 24.The first nozzle 32 also includes a top or upper surface 104 includingone or more apertures 106 through which solder exits or is expelled toform a wave 110 (e.g., first wave). The front and rear walls may serveto contain solder as it travels from the solder reservoir 24 through theone or more apertures 106. The first nozzle 32 may also include a frontflange 112 over which solder may flow or travel back into the solderreservoir 24 in the absence of the solder return apparatus 100.

It has been discovered (in the absence of the solder return apparatus100) that solder 108 cascading off the solder nozzle 32 (e.g., off thefront flange 112) directly into the solder 108 in the solder reservoir24 (i.e., the solder 108 contacts nothing between the time it leaves thesolder nozzle 32 and contacts the solder 108 in the solder reservoir 24)splashes upon impact with the solder 108 in the solder reservoir 24.This is in large part due to the velocity (and momentum) the solder 108has attained by the time it reaches the solder 108 in the solderreservoir 24 after it cascades off the first nozzle 32. The splashingsolder 108 has been shown to contact and stick to components of the wavesoldering apparatus 10 (e.g., the nitrogen hood) and the electronicsubstrate 20 causing solder balls and droplets. For instance, it hasbeen discovered that solder balls can form under components of theelectronic substrate (e.g. SMT, BGA) which can cause metal shorts (e.g.,between legs of fine pitch SMT components). The splashing solder 108 mayresult in wasted solder, high defects rates in relation to theelectronic substrates 20, and the like. As will be discussed in moredetail below, use of the solder return apparatus 100 may reduce theaforementioned splashing of solder and/or limit the effects of anysplashing that does occur which may reduce the wasting of solder andelectronic substrate defect rates, among other advantages.

The solder return apparatus 100 may broadly include a mounting member orsection 114 for mounting (e.g., permanently, removably) the apparatus100 to the first nozzle 32 and a collection member or section 116 forreceiving the solder 108 from the first nozzle 32 and returning thesolder 108 to the solder reservoir 24. The mounting section 114 may bein the form of a plate that may be laid or otherwise draped over thefirst nozzle 32. More specifically, the mounting section 114 may includea first segment 118 that may be mounted and/or laid over the uppersurface 104 of the first nozzle 32 and second segment 120 that may bemounted and/or laid over the front flange 112 of the first nozzle 32.The first segment 118 may include at least one aperture 122 that may bealigned with the one or more apertures 106 in the upper surface 104 ofthe first nozzle 32 to thereby allow solder to well up through theapertures 106 and the aperture 122 to form the wave 110.

The first segment 118 may also include any appropriate mountingmechanism for mounting the mounting section 114 (and thereby theapparatus 100) to the first nozzle 32. For instance, the mountingmechanism may be in the form of one or more bores 124 that extendthrough the first segment 118 (e.g., from a top to a bottom surface ofthe first segment 118). Corresponding bores (not shown) may be formed inthe upper surface 104 of the first nozzle 32. In assembly, the firstsegment 118 may be laid over the upper surface 104 such that theaperture 122 is at least generally aligned over the apertures 106 andthe bores 124 are at least generally aligned over the correspondingbores in the upper surface 104. The bores 124 and those in the uppersurface 104 may be threaded. In any event, fasteners (e.g., threadedbolts) may be extended through the bores 124 and those in the uppersurface 104 to secure the apparatus 100 to the first nozzle 32. Othermounting mechanisms are also envisioned such as snaps, detents, and/orthe like.

The second segment 120 may be designed to generally follow the shape ofthe front flange 112 of the first nozzle 32 so as to hang over the frontflange 112. With particular reference to FIG. 4, each of the secondsegment 120 and front flange 112 may be of a generally curvilinear shapeor design that slopes generally from the upper surface 104 of the firstnozzle 32 towards a bottom of the solder reservoir 24. Matching orgenerally matching the profile or shape of the second segment 120 to thefront flange 112 allows the apparatus 100 to achieve a more stable fitwhen it is mounted over the first nozzle 32. Additionally, this allowssolder 108 rising through the upper surface 104 to return to the solderreservoir 24 at a decreased velocity (e.g., more gradually as comparedto the solder 108 leaving the upper surface without the front flange 112and second segment 120 and cascading directly into the solder reservoir24). It should be appreciated that the second segment 120 may have sucha curvilinear or sloped design even in the absence of the first nozzle32 having a front flange 112.

Additionally and with particular reference to FIG. 3, the mountingsection 114 may be of a length or width (depending upon one'sperspective) such that it extends substantially from one end of theupper surface 104 to the other end (e.g., from the first side plate 52to the second side plate 54), or otherwise covers substantially theentire area where solder 108 flows out of the apertures 106. This mayallow the apparatus 100 to pass substantially all solder 108 exiting thefirst nozzle 32 into the collection section 116 for eventual transfer tothe solder reservoir 24.

With continued reference to FIGS. 3 and 4, the collection section 116may be appropriately connected or attached to the mounting section 114(e.g., via welding, as part of a casting process) in such a manner thatsolder 108 welling up through the apertures 106, 122 pours or flows overthe second segment 120 and into the collection section 116 (e.g., as inFIG. 4). Broadly, the collection section 116 may include a trough 126(e.g., cup, receiving area) for collecting and/or containing an initialrunoff of the solder 108 from the first nozzle 32. The trough 126 may beof any appropriate form including a bottom wall 128 and a number ofwalls extending upwardly therefrom (e.g., first and second end caps orside walls 130, 132 and front wall 134). The trough 126 may beconsidered an “upper stage” of the collection section 116. The trough126 may be located about halfway of the distance that solder 108 needsto drop to return to the solder reservoir 24. That is and withparticular reference to FIG. 4, a distance 136 from a top of the solder108 in the solder reservoir 24 to the bottom wall 128 may be about halfof a distance 138 from the top of the solder 108 in the solder reservoir24 to the area (e.g., upper surface 104) at which the solder 108cascades from the first nozzle 32. This may allow the trough 126 toreduce the velocity and momentum of the solder 108 which may reducesplashing when the solder 108 eventually contacts the solder 108 in thesolder reservoir 24. Additionally, such relative positioning of thetrough 126 may sufficiently contain the solder 108 (i.e., limit thesolder 108 from flowing over the side and front walls 130, 132, 134).Other locations of the trough 126 relative to the upper surface 104 andthe top surface of the solder 108 in the solder reservoir 24 are alsoenvisioned.

With reference again to FIGS. 3 and 4, the bottom wall 128 may includeat least one aperture, opening or slot 140 therethrough that allowssolder 108 received in the trough 126 to eventually flow into the solderreservoir 24. The slot 140 may extend substantially from the first sidewall 130 to the second side wall 132 although other slot shapes anddesigns are encompassed within this disclosure. For instance, a numberof slots may be defined through the bottom wall 128 each of whichextends generally from the front wall 134 towards the second segment120. In any event, solder 108 passing through the slot 140 flows into achamber 142 (e.g., a “lower stage”) which may serve to reduce andcontain splashing of the solder 108 and return the solder 108 to thesolder reservoir 24 as will be described below.

The chamber 142 may be at least partially defined by the bottom wall 128and any appropriate flow control member 144. The flow control member 144serves to adjustably control a quantity of solder 108 exiting the slot140. Additionally, the flow control member 144 may serve as a “secondstep” (the bottom wall 128 of the trough 126 being the “first step”)that again serves to reduce the velocity of solder 108 exiting the slot140 because the solder 108 first contacts the flow control member 144instead of falling directly from the slot 140 into the solder 108 in thesolder reservoir 24. For instance, the flow control member 144 may be inthe form of an adjustable plate 146 having a length and width at leastabout as great as a length and width of the slot 140.

With reference to FIG. 4, the adjustable plate 146 may be selectivelymovable towards and away from the slot 140 along a path 148. Forinstance, positioning of the adjustable plate 146 closer to the slot 140may serve to reduce the quantity of solder 108 exiting the slot 140while positioning of the adjustable plate 146 farther away from the slot140 may serve to increase the quantity of solder 108 exiting the slot140. Additionally, positioning of the adjustable plate 146 closer to theslot 140 may allow the solder 108 to attain a first velocity afterleaving the adjustable plate 146 and before contacting the solder 108 inthe solder reservoir 24 while positioning of the adjustable plate 146farther away from the slot 140 may allow the solder 108 to attain asecond velocity after leaving the adjustable plate 146 and beforecontacting the solder 108 in the solder reservoir 24 that is less thanthe first velocity. This may result from the solder 108 having a shorterdistance to drop when the adjustable plate 146 is farther away from theslot 140 compared to when the adjustable plate 146 is closer to the slot140. It should be appreciated that the adjustable plate 146 may beappropriately positioned based on a number of factors including but notlimited to the flow rate and type of solder 108 or other liquid exitingthe first nozzle 32, the distance 136 between the bottom wall 128 andthe solder 108 in the solder reservoir 24, and/or the like.Additionally, while the adjustable plate 146 has been shown to begenerally parallel to the bottom wall 128 of the trough 126, otherorientations are also contemplated.

As illustrated, adjustability of the plate 146 may be provided by way ofa number of fasteners 150 (e.g., threaded fasteners or studs) that arerespectively inserted through portions of the trough 126. For instance,each fastener 150 may be appropriately secured (e.g., rigidly) to asurface of the adjustable plate 146 (e.g., via welding, riveting) so asto extend or protrude away from such surface. The trough 126 may includea number of mounting tabs 152 (e.g., stiffening ribs) that areappropriately formed or positioned in the slot 140, each having at leastone aperture (not shown) that is adapted to receive a fastener 150.Additionally, a threaded nut 154 may be disposed or positioned on eachmounting tab 152 over the apertures also for receipt of a fastener 150.

In assembly, the fasteners 150 may initially be positioned through theapertures of the mounting tabs 152 in a direction from the bottom wall128 towards a top of the trough 126 where soldier would enter the trough126. Thereafter, the nuts 154 may be threaded over the ends of thefasteners 150 to a desired location on the fasteners 150, and then theoperator may release the adjustable plate 146 and fasteners 150 suchthat the nuts 154 on top of the mounting tabs 152 rest on top of themounting tabs 152 and the adjustable plate 146 hangs below the bottomwall 128. Thereafter, adjustment of the adjustable plate 146 towards andaway from the slot 140 may be accomplished by selectively rotating oneor more of the nuts 154 clockwise or counterclockwise. It should benoted that the fasteners 150 need not necessarily be extended throughapertures on mounting tabs 154 disposed within the slot 140. Forinstance, the slot 140 may be free of mounting tabs 154, and thefasteners 150 may be extended through apertures that extend through thebottom wall 128. Other arrangements are also encompassed by thisdisclosure.

As mentioned previously, the chamber 142 may be at least partiallydefined by the bottom wall 128 and the adjustable plate 146.Additionally, the chamber 142 may include other features that serve tolimit solder droplets from contacting the electronic substrate 20, othercomponents of the wave soldering apparatus 10, and/or the like. Forinstance, a deflection plate 156 may be appropriately mounted or formedas part of the collection section 116 and may further define the chamber142. The deflection plate 156 may be mounted to (e.g., via welding) orform part of the front wall 134 and extend downwardly therefrom. Asshown, the deflection plate 156 may be designed or be of such dimensionssuch that it extends into the solder 108 of the solder reservoir 24, andmay be generally perpendicular to the top surface of the solder 108 inthe solder reservoir 24 and/or the adjustable plate 146. In somevariations, the deflection plate 156 may be disposed at angles otherthan about 90° relative to the top surface of the solder 108 in thesolder reservoir 24.

With particular reference now to FIG. 4, it can be seen that solder 108flowing through the slot 140 is substantially limited in its ability tosplash outwards towards unintended components by way of the chamber 142.More specifically, the chamber 142 may be defined by the bottom wall 128which generally faces the adjustable plate 146, and the front wall 102of the first nozzle 32 which generally faces the deflection plate 156.The chamber 142 may serve to at least partially shield the electronicsubstrate 20 and other components of the wave soldering apparatus 10from splashing solder 108. Turning back to FIG. 3 and although notillustrated, it is further contemplated that similar deflection platescould be mounted to the first and second side walls 130, 132 anddesigned so as to extend into or close to the solder 108 of the solderreservoir 24 to limit solder 108 from splashing or spraying laterallyaway from the collection section 116. In any event and with reference toFIG. 4, solder 108 exiting the trough 126 via the slot 140 may bedirected over the adjustable plate 146 and into the solder reservoir 24for eventual return to the first wave soldering assembly 28 and thefirst nozzle 32 whereby the solder 108 can again form the wave 110.

Turning now to FIGS. 5 and 6, another embodiment of a solder returnapparatus 100′ is illustrated for returning solder 108 to the solderreservoir 24 while limiting the ability of the solder 108 to splash andspray onto the electronic substrate 20 and other components.Corresponding components between the embodiments of FIGS. 3-4 and 5-6are identified by common reference numerals. Those correspondingcomponents that differ in at least some respect from the embodiment ofFIGS. 3-4 are identified by a “single prime” designation in FIGS. 5-6.As with the apparatus 100, the one or more components of the apparatus100′ may be of any appropriate size, shape, configuration and/or type.One difference between the apparatus 100 of FIGS. 3-4 and the apparatus100′ of FIGS. 5-6 is a quick-mount member 200 that may serve to mount(e.g., removably) the collection member 116 to a preexisting structureof the first nozzle 32 and/or the solder reservoir 24.

With reference to FIG. 6, it can be seen that a preexisting structuresuch as a wall 202 extends upwardly out of the solder 108 in the solderreservoir 24 and may be considered a portion of the solder reservoir 24or even the first nozzle 32. The wall 202 may be appropriately mountedwithin or form a part of the solder reservoir 24 or the first nozzle 32so as to protrude upwardly out of and/or away from the solder 108 in thesolder reservoir. For instance, the quick mount member 200 may be a hookmember 204 that is appropriately interconnected to the front wall 134′of the trough 126′ (e.g., via welding, as part of the manufacturingprocess) and/or integrally formed therewith. The hook member 204 may behung over the wall 202 as part of the process of mounting the apparatus100′ to the first nozzle 32. Once the hook member 204 has been hangedover or attached to the wall 202, the wall 202 may serve a similarpurpose to the deflection plate 156 discussed in relation to FIGS. 3-4.The apparatus 100′ may be useful as part of a rotary chip wavearrangement or any other arrangement including a preexisting structureover which the quick-mount member 200 can be attached. Additionally, thequick-mount member 200 may include other structures and arrangementssuch as apertures and bolts, tabs, and/or the like.

Many other arrangements of the apparatuses 100, 100′ discussed hereinare also envisioned. In one arrangement, either of the apparatuses 100,100′ could include a second collection section 116, 116′ attached to arear side of the mounting section 114 which could be a mirror image ofthe first collection section 116, 116′ and be designed to hang off arear side of the first nozzle 32 or any other nozzle that may utilizethe apparatuses 100, 100′. This may advantageously serve to collect andcontain solder 108 that has flowed off a back or rear side of the nozzleand return such solder back to the solder reservoir 24. In onevariation, an apparatus could have a collection section 116 on one sideand a collection section 116′ on the other side.

In another arrangement, multiple apparatuses 100, 100′ could be attachedto the same nozzle. For instance, one apparatus 100 or 100′ could bemounted onto a nozzle for collecting solder runoff on the front side ofthe nozzle, and then a second apparatus 100 or 100′ could be mountedonto the nozzle for collecting solder runoff on the back side of thenozzle. The respective mounting sections 114 of the two apparatuses 100and/or 100′ could have aligned holes such that fasteners could beinserted through the aligned holes and then into the upper surface 104of the first nozzle 32 or other nozzle. It should also be appreciatedthat the apparatuses disclosed herein are not limited to use with solderand may be used in conjunction with nozzles expelling or releasing othertypes of flowing liquids in situations where it may be advantageous tocontrol return of the liquids to a source or other location whilelimiting the splashing or spraying of the liquid into unintendedlocations.

The apparatuses disclosed herein can be constructed of any appropriatematerials and combinations of such materials via any appropriatemanufacturing methods. For instance, the apparatuses may be constructedof any sturdy materials that limit the degree to which solder can stickto the surface of the apparatus. Materials such as stainless steel,titanium and/or the like have been found to be suitable materials.Additionally, any appropriate manufacturing methods and combinations ofsuch methods may be utilized to construct the apparatuses such ascasting, forming, machining, welding and/or the like.

Turning now to FIG. 7, one method (300) of using a wave solderingmachine (e.g., in conjunction with one of the apparatuses disclosedherein) is disclosed although it should be appreciated that othermethods of use are also envisioned. Initially a wave solder machine maybe operated (302) to pump solder from a solder reservoir through atleast one aperture of a solder nozzle to form a solder wave (e.g., wave110 in FIGS. 4 and 6). The solder may be received (304) from the wave ina trough that is interconnected to the solder nozzle and generallysituated between the nozzle and the solder in the solder reservoir. Seetrough 126, 126′ in FIGS. 3-6. For instance, a bottom wall of the troughmay be located about halfway between an upper surface of the nozzle andthe solder in the solder reservoir. The solder may be allowed to flow(306) through an opening (e.g., an elongated slot) in the bottom wall ofthe trough and towards the solder reservoir.

The solder may be received (308) on a plate and then allowed (310) toflow into the solder reservoir whereby the wave solder machine cancontinue to be operated (302) to pump solder from the reservoir throughthe nozzle. The plate may be situated below the bottom wall of thetrough and above the solder in the solder reservoir. In this regard, thesolder may be thought of as traveling over a series of “steps” (e.g.,the bottom wall, the plate) that serve to gradually reduce the velocityof the solder and contain the solder on its return to the solderreservoir from the nozzle to limit the solder from splashing or sprayingonto an electronic substrate and/or components of the wave solderingmachine.

At any appropriate time (e.g., once the solder wave has been created),an electronic substrate may be sent past the solder wave (e.g., via aconveyor) such that, for instance, a lower or bottom surface of thesubstrate contacts the wave. See electronic substrate 20 travelingthrough wave 110 in FIG. 4. Additionally, the plate may be adjustedtowards and/or away from the opening in the bottom wall of the trough toany desired position. For instance, if too much solder is filling thetrough such that solder is flowing over one or more walls of the tough,the plate can be adjusted away from the bottom wall to increase the rateat which solder empties the trough. If solder is exiting the trough tooquickly such that solder is somehow splashing on its return to thesolder reservoir in a manner that allows solder droplets to contactelectronic substrates and/or wave soldering machine components, theplate can be adjusted towards the bottom wall to reduce the flow rate ofsolder exiting the trough. Operators may readily determine anappropriate position of the plate relative to the trough and/or thesolder in the solder reservoir.

The inventors have found that without using the solder returnapparatuses disclosed herein, splashing solder (e.g., resulting from thesolder cascading over the front of the solder nozzle directly into thesolder reservoir with nothing slowing down the solder in between) cancontact wave soldering machine components (e.g., nitrogen hoods) andelectronic substrates (e.g., printed circuit boards) creating solderballs on such components and substrates. In the case of printed circuitboards, solder balls can get under components (e.g., SMT, BGA) causingmetal shorts and hence high defect rates in relation to the printedcircuit boards as a whole. However, use of the solder return apparatusesdisclosed herein has been shown to reduce such splashing of solder andreduce the aforementioned high defect rates which may result in higherprofitability for companies and organizations utilizing wave solderingmachines.

The features described herein present numerous advantages when used insituations where it is desirable to reduce splashing and spraying of aliquid as it leaves or is expelled from a nozzle or other similarstructure. As noted above, the curvilinear design of the second segmentof the mounting section initially slows down the solder after it hasleft the nozzle as it travels towards the solder reservoir. The troughof the collection section is situated at a distance higher than thesolder reservoir but below the upper surface of the solder nozzle whichprovides an initial receiving area for the solder that reduces thevelocity of the solder before its eventual entry into the solder in thesolder reservoir. The one or more openings/slots in the bottom wall ofthe trough allow the solder to enter a substantially shielded chamber,and a flow control member such as a plate may be adjusted towards andaway from the opening/slot to control the quantity of solder exiting theslot. The flow control member also serves to reduce the velocity of thesolder on its travel between the trough and the solder in the solderreservoir as the solder contacts the flow control member before iteventually drops into the solder in the solder reservoir; this mayfurther serve to limit splashing. One or more deflection plates mayextend into the solder in the solder reservoir to further limit anysolder balls and droplets generated from the solder entering the solderreservoir from contacting electronic substrates and other components.

While only a single flow control member has been discussed herein, it isenvisioned that additional flow control members could be included aspart of the solder return apparatuses 100, 100′. For instance, a secondflow control member (e.g., adjustable plate) could be adjustably mountedbelow the first flow control member (e.g., via one or more threadedfasteners) and could form a “third step” over which the solder 108travels to further reduce the velocity of the solder 108 before itsreturn to the solder in the solder reservoir.

Any of the embodiments, arrangements, or the like discussed herein maybe used (either alone or in combination with other embodiments,arrangement, or the like) with any of the disclosed aspects. Merelyintroducing a feature in accordance with commonly accepted antecedentbasis practice does not limit the corresponding feature to the singular(e.g., indicating that the device includes “the collection section”alone does not mean that the device includes only a single collectionsection). Moreover, any failure to use phrases such as “at least one”also does not limit the corresponding feature to the singular (e.g.,indicating that a container includes “a collection section ” alone doesnot mean that the container includes only a single collection section).Use of the phrase “at least generally,” “at least partially,”“substantially” or the like in relation to a particular featureencompasses the corresponding characteristic and insubstantialvariations thereof. For example, a plate that is “substantiallyperpendicular” to something else covers both an insubstantial variationof the plate being perpendicular in addition to the plate beingperpendicular. Finally, a reference of a feature in conjunction with thephrase “in one embodiment” does not limit the use of the feature to asingle embodiment.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and description isto be considered as exemplary and not restrictive in character. Forexample, certain embodiments described hereinabove may be combinablewith other described embodiments and/or arranged in other ways (e.g.,process elements may be performed in other sequences). Accordingly, itshould be understood that only the preferred embodiment and variantsthereof have been shown and described and that all changes andmodifications that come within the spirit of the invention are desiredto be protected.

What is claimed is:
 1. A method of using a wave solder machine,comprising: operating the wave solder machine to pump solder from asolder reservoir through at least one aperture of a solder nozzle toform a solder wave; receiving solder from the solder wave in a troughthat is interconnected to the solder nozzle; allowing the solder to flowthrough an opening in a bottom wall of the trough, wherein the bottomwall is disposed above a surface of solder in the solder reservoir andbelow the at least one aperture of the solder nozzle; receiving, afterthe operation of allowing the solder to flow through the opening in thebottom wall of the trough, the solder on a plate disposed above thesurface of solder in the solder reservoir and below the bottom wall ofthe trough; limiting, with the plate, substantially all of the solderfrom falling through the opening in the bottom wall of the troughdirectly into the solder in the solder reservoir; and allowing thesolder to flow from the plate into the solder reservoir.
 2. A method ofusing a wave solder machine, comprising: operating the wave soldermachine to pump solder from a solder reservoir through at least oneaperture of a solder nozzle to form a solder wave; receiving solder fromthe solder wave in a trough that is interconnected to the solder nozzle;allowing the solder to flow through an opening in a bottom wall of thetrough, wherein the bottom wall is disposed above a surface of solder inthe solder reservoir and below the at least one aperture of the soldernozzle; receiving, after the operation of allowing the solder to flowthrough an opening in a bottom wall of the trough, the solder on aplate; allowing the solder to flow from the plate into the solderreservoir, wherein the plate is disposed above the surface of solder inthe solder reservoir and below the bottom wall of the trough; andadjusting the plate at least one of towards and away from the bottomwall of the trough.
 3. The method of claim 1, further comprising: movingan electronic substrate over the solder nozzle.
 4. The method of claim3, further comprising: moving a bottom surface of the electronicsubstrate through the solder wave.
 5. The method of claim 1, furthercomprising: receiving solder from the trough in the reservoir; andcontinuing to operate the wave solder machine to pump the solderreceived in the reservoir from the trough through the at least oneaperture of the solder nozzle to form the solder wave.
 6. The method ofclaim 1, wherein the plate is disposed substantially parallel to thesolder surface.
 7. The method of claim 6, wherein the plate is disposedsubstantially parallel to the bottom wall of the trough.
 8. The methodof claim 1, wherein the plate is disposed substantially parallel to thebottom wall of the trough.